Renal lymphoma: spectrum of CT findings and potential mimics.

Renal lymphoma has a broad spectrum of imaging manifestations. Typical patterns of renal lymphoma include multiple renal masses, solitary masses, diffuse infiltration, and invasion from contiguous retroperitoneal disease. Isolated perirenal disease is probably the most atypical form of renal lymphoma and has a variety of appearances, including small curvilinear densities and soft-tissue nodules or plaques. In general, the CT diagnosis of renal lymphoma is not difficult because most patients already have a known diagnosis of lymphoma. Nevertheless, it is important to be familiar with both the typical and the atypical manifestations of renal lymphoma because numerous disease processes, normal variants, and artifacts may potentially mimic renal lymphoma.